In this second and last part of this very personal review of the Performance Mouse MX, I'll be discussing two other features of this mouse, as well as wrap up with a few additional thoughts.

Thumb area and buttons
Logitech has been clearly experimenting with the thumb rest design for some time. The Performance Mouse MX is the latest of a series of 4 mouses (that I'm aware of) that brings this feature in which the thumb side of the mouse is designed as an inset area with a large rest base. For your information, they were the MX 1000, MX 1100, MX Revolution and now the Performance MX. There's also a gaming mouse featuring this inset (the G700), but it isn't so pronounced neither I factor it in the range of professional or user desktop mice.

The thumb depression area has been deepened with each model. But I don't think they can do much more than what they did with the Performance MX without it becoming ridiculous. As is right now, the thumb finds itself in a comfortable position and completely out of the surface where the mouse sits. But there's a few caveats.

The first one is it works better for slender fingers. The mouse wasn't designed for fat fingers. Not because the resting area isn't big enough (it should fit many type of thumbs except the largest), but because Logitech decided to place a zoom button right on the top ridge that will in fact come in permanent contact with any large thumb. This will remove some of the comfort and possibly even cause some muscle or skin irritation.

The second caveat is the repeated decision to make this area rubberized. No doubt made with the best intentions (it actually feels nice and comfy), but rubber is very adherent while also sensitive to acids. For anyone suffering from easy to sweat hands, this will shorten considerably the mouse life as well as having the potential to become an health hazard, since it is inevitable that the rubber will sooner or later start to decompose as well as collecting germs. Particularly during the summer, don't use this mouse for long gaming sessions and do not allow yourself to use the mouse with a sweaty hand. Just rub it dry against your trousers or the face of anyone annoying you. I would also advise to wash your hands several times a day, but I would probably sound like a mom. Incidentally the pinky and ring fingers area is also rubberized. I wished Logitech didn't do this...

The Performance MX puts all the button action on this thumb rest area, leaving only the right and left click to their be their usual self. Directly above there's a zoom button and the back and forth buttons typical of so many mice. The zoom button is an activation button that you click to enable zooming and can them release your thumb from it. From there you use the scroll wheel to zoom in our out, clicking the zoom button again to go back to do what you intend to do when you are done. Very practical for graphics artists, I'd guess. Being that I'm only an occasional visitor to this type of software, use for me is a bit more limited and am planning on eventually remapping it.

The 4th button is an hidden button that you activate by simply pressing your thumb against the base of the thumb rest. This is actually an excellent spot to have a button since, as you press this button with your thumb, your muscles reflex will tighten the grip against the mouse and press it against the table (in contrast, the zoom button tends to make you move the mouse as you press it). So, I remapped this new button to be my DIP switcher for those gaming sessions. And I must say it works like a charm! The default behavior of the mouse is to sort of imitate the Windows Aero Task Switcher; the one you get with the Windows Key + Tab combo.

Remapping these 4 buttons is, of course, done through Logitech's SetPoint. Which means, you can't capture the windows key yet. It's an annoyance. Particularly for those of us who would like to map mouse buttons to such things as Windows+D (show desktop).

Ergonomics, or the Performance Mouse MX skyline
I'm not an expert on ergonomics by far, neither I'm totally convinced any advise I could give (were I an expert) would fit the bill of the reader. I've followed enough expert advise on ergonomics that didn't work for me, I could probably write a book about it. So, rest assured I won't be lecturing here.

The Performance Mouse MX presents itself clearly with a design towards ergonomics. But like with every other device, it will fail on the hands of the wrong person. And the wrong person isn't one not caring about their comfort. Simply someone with the "wrong" type of hand.

This is a palm rest mouse (my favorite). It is designed so that your palm, middle and index fingers rests entirely on the mouse top surface. You won't be using it much with a claw grip mouse and definitely not with a fingertip grip. Palm grips come with the advantage that they exert more downward pressure on the mouse as well as a tendency to relax the hand on top of it (which is why that pressure is exerted). On many people this allows for a better control of the mouse as well as prolonged usage without tiring the hand. With the help of a thumb rest area, these mice are a marvel to use. Very comfortable and very precise.

However palm grip mice suffer from the most sensitivity to hand sizes. And the Performance MX is no different. A large hand will find itself being invited to palm rest due to the pronounced curvature of the top area, but will however see the sides of the hand completely off if the mouse isn't wide enough. A long hand, will want to palm grip, but find their middle and index fingers off the mouse if the mouse isn't long enough, forcing the user to claw grip instead or to slide the palm grip downwards towards the user and eventually connecting the base of the palm against the table. All of these can turn a good mouse into an array of experiences starting in the mildly annoying area, and ending in the downright frustrating.

The Performance MX is a medium sized mouse that will fit small to medium hands. The mouse suffers from not being wide enough in my opinion. Should be a bit wider. But it has a good lengthy surface, so my long and slender hands and fingers can still find themselves in a comfortable position. Unfortunately it wasn't designed with plump, very wide or large hands in mind, and I wouldn't advise it if that's your case. As noted before, the thumb rest also betrays this design since it won't work so well for fatty thumbs.

One last thing to take into consideration regarding palm grips is your working conditions. I always found it that, on my case, for this type of grip to be fully effective, the mouse should be positioned deep in the table, with enough room for the forearm to rest on the table. If my working conditions require the mouse to be placed more towards my edge of the table, the experience will suffer since the palm grip will actually tire my arm very quickly since it can't rest. On those circumstances I tend to slide my palm grip downwards (towards myself) and rest my wrist against the table instead. Due to these mice curvature, that will force you to adopt just a hint of a claw grip so it slides more freely. Of course, this won't be as good as a complete palm grip. But you should be aware of this and not think you are doing something wrong because the palm grip is tiring you very quickly. You probably aren't. It's just that you are using the mouse closer to the edge of the table and that won't work well with this grip.

Final Thoughs
The Performance Mouse MX is a good mouse and a welcomed development over the shortcomings (or should I say the overdoings) of the Revolution MX. But there's some things that are really hard to explain.The top one: the Performance MX is a loud mouse. The main buttons are annoying, but he scroll wheel is offending. Logitech has a thing for making loud mouses. But when you see a mouse tagged at $99, you expect better.

Overall I wouldn't want any other mouse at this moment. This one just fits the bill perfectly and I don't think there's anything much better out there that still looks like a mouse and doesn't make me look bad in front of my friends. But this is still not what I want from a professional mouse. If I was asked what I could do to improve the Performance MX, Id' say:

- No zoom button, thank you
- No back and forth buttons, thank you
- No rubberized surfaces, thank you
- A wider palm surface, please
- A silent mouse, please